Exposure meter for print-making apparatus



May 7, 1946. G. M. DYE 22,99,992

EXPOSURE METER FOR PRINT MAKING APPARATUS Original Filed Aug. 4, 1942 TSheets-Sheet 1 EXPOSURE METER FOR PRINT MAKING APPARATUS Original Filed Aug. 4', 1942 7 Sheets-Sheet 2 & /445% any/m:

May 7, 1946. I D 2399,992

EXPOSURE METER FOR PRiN'I MAKING APPARATUS Original Filed Aug. 4, 1942 7 Sheets-Sheet 3 May 7, 1946. r G. M,- DYE I EXPOSURE METER FOR PRINT MAKING APPARATUS I Original Filed Aug. 4, 1942 '7 Sheets-Sheet 4 May 7, 1946.

G. M. DYE

EXPOSURE METER FOR PRINT MAKING APPARATUS Original Filed Aug. 4, 1942 7 Sheets-Sheet .5

Gui/y 17/15 1/ Z May 7, 1946. G. M. DYE 2399,992

EXPOSURE METER FOR PRINT MAKING APPARATUS Original Filed Aug. 4, 1942 7 Sheets-Sheet 6 May 1,194 G. M. DYE 22 99,992

EXPOSURE METER FOR PRINT MAKING APPARATUS Original Filed Aug. 4, 1942 7 Sheets-Sheet 7 Patented May 7, 1946 EXFOSURE METER FOR PRINT-MAKIN APPARATUS Glen M. Dye, Minneapolis, Minn.

Original application November 7, 1938. Serial No. 239,269, now Patent No. 2,291,613, dated August 4, 1942. Divided and this application July10,

. 1942, Serial No. 450,397

8 Claims.

This invention relates to a projection printer for making photographic prints or to a machine for making oversized prints. The machine is designed to make projection prints from negatives of different sizes, which prints will have a size range comprising a very large proportion of such projection prints or enlargements now commercially made.

This is a division of copending application No. 239,269, filed November 7, 1938, now patent No. 2,291,613, of August 4, 1942.

It is an object of this invention to provide a motor driven projection printer which is constructed and arranged for rapid, convenient and efllcient operation.

Another important object of the invention is the provision of a novel exposure guide device for use in accurately controlling a suitable printing exposure.

It is still another object of the invention to provide a projection printer equipped with an exposure meter having a graduated density scale and a member in plain view of the operator moved along said scale during the printing period so that the position of said member will show the length of the exposure or printing period.

It is a further object of the invention to provide a projection printer equipped with an exposure meter comprising a series of density indica-tions, a member movable along the same, means for starting the movement of said member at the same time the printing operation is started, and means under the control of the operator for terminating the printing period.

These and other objects and advantages of the invention will be fully set forth in the following description made in connection with the accompanying drawings in which like reference characters refer to similar parts throughout the several views and in which:

Fig. 1 is a view in front elevation of the machine; r

Fig. 2 is a view in side elevation as seen from the right of Fig. 1;

Fig. 3 is a plan view of the machine;

Fig. 4 is a view partly in side elevation and partly in vertical section of the driving mechanism, a section being taken through the lower part of the clutch and the enclosing casing;

Fig. 5 is a horizontal section taken through the top of the casing enclosing the driving parts and showing the driving parts in plan;

Fig. 6 is a vertical section taken through the casing enclosing the driving parts showing the driving parts in side elevation, some parts being shown in section;

Fig. 7 is a vertical section through the casing enclosing the clutch showing the clutch and friction mechanism in side elevation;

Fig. 8 is a fragmentary view showing the tripping mechanism for the printing lamp switch;

Fig. 9 is a vertical section taken centrally through the lamp box;

Fig. 10 is a vertical section taken centrally through the lamp box in a plane at right angles to that to which Fig. 9 is taken;

Fig. 11 is a plan view showing an exposure guide device, the enclosing casing being shown in horizontal section;

Fi 12 is a view in front elevation of the exposure guide device;

Fig. 13 is a vertical section through the exposure guide device;

Fig, 14 is a vertical section through a portion of the exposure guide device; and

Fig. 15 is a vertical section taken on line 3B36 of Fig. 13 as indicated by the arrows.

Referring to the drawings a machine is shown comprising a frame including legs 50 shown as four in number. These may be of any suitable construction and are illustrated as of angle shape in cross section tapering toward their lower ends with the inside of their angles disposed inwardly and secured at their upper ends by screws 5| to a substantially horizontal plate or table 52 having a depending flange 52a extending thereabout with the inner side of which legs 50 engage. A bar 53 of angular cross section extends between legs 50 at one side adjacent their bottoms and another bar or plate 54 extends between the pair of legs at the opposite side adjacent the bottom thereof. A bar 55 shown as angular in cross section is also secured to and extends between the rear legs 50 adjacent their bottoms. A plate 56 having upturned flanges at its edges is secured to bars 53 and 55 and an electric motor 51 is supported by and secured to plate 56. A pulley 58 is secured to the armature shaft of motor 51 and has a belt 59 running thereover which also runs over a pulley 60 secured to a shaft 6| journaled in a bearing 62a carried on a plate 62, Plate 62 forms part of a clutch frame and is supported upon posts 63 shown as four in number and is secured thereto by headed screws 64. Posts 83 seat on plate 58 and are secured thereto by the screws 64. Shaft 6| has a worm gear 65 secured thereto which meshes with a worm wheel gear 66 secured to a shaft 61 journaled in a bearing 68 carried by plate 62. A clutch plate 69 is secured to the end of shaft 61 and when the machine is in operation is continuously driven from motor 51. Plate 69 cooperates with another clutch plate 10 adapted to be brought into engagement therewith at certain times and to be driven thereby. Plate 10 will have some suitable friction material 10a thereon and is secured to a shaft 1| Journaled in a bearing 12 carried by plate 66. An arm 13 is pivotally connected to a link H, the other end of which is secured to an arm 16 having a hub secured in any suitable manner as by pin 16 to a shaft 11. Shaft 11 is journaled in a bearing 18 secured in plate 56 and has an enlarged portion above said plate extending into and secured in the lower end of a tubular shaft 18. Shaft 19 extends vertically adjacent one side of the machine and is secured to a pulley block which has a reduced portion, journaled in an opening in a casing top [22a to be later described, The clutch comprising plates 69 and 10 is a half revolution clutch and includes a third plate 8| having downturned ears at opposite sides and to which are secured studs having journaled thereon rollers 83. Plate 8| has apertures at either side through which extend studs 10b secured to and depending from plate I0, said studs having pins 84 extending therethrough below plate 8|. Compression coiled springs 85 surround studs lb engaging plate at their upper ends and plate 8| at their lower ends. The plate 56 has spaced openings 56a therein spaced the same distance as the rollers 83 and into which rollers 83 are adapted to drop to determine the half revolution period of the clutch. Said clutch is adapted to be actuated by a toe trigger or pedal 86 oscillatable about the axis of a rod or shaft 81 journaled in small blocks 88 secured to the underside of plate 56. A bar 89 is secured to shaft 81 by which the trigger plate 86 is carried and an arm 90 is secured to and extends rearwardly from bar 89 and carries clutch actuating arts adapted to raise plate 8|. The trigger plate also has upstanding therefrom a stud 9|. A tensile coiled spring 92 is secured at one end to a projection on plate 60 and is secured at its other end to the upper end of stud 9| and said spring acts to hold trigger plate 86 in its raised or inoperative position. When trigger plate 96 is pressed downwardly by the toe of the operator to its lower position the clutch makes one-half a revolution and arm I3 also makes a half revolution or rotates through 180 degrees. A box-like cover 56d fits over the flange on plate 56 and forms an enclosure for the motor and clutch parts. The specific construction of the clutch need not be further described as it per se forms no part of the present invention. A casing 60a secured to plate 56 encloses arm 15.

A lamp box is provided, the top of which is formed by a plate or casting 52b which is secured in and in effect forms part of table top 52. Said plate 52?) has a flange 520 at its forward end having therein a slot or opening 52d which is continued as a slot through the bottom of plate 525 for some distance. Said plate 52?) has a raised portion 52e therein and a trough 52] is formed at the front portion of the plate 52b between flange 52c and portion 52c. Portion 52c is apertured and has 9. depending cylindrical flange 52g extending downwardly therefrom. An annular flange 52h. is formed in portion 62c and forms the support for a lens 93. Said lens may be positioned on a resilient annular strip 94 shown as circular in cross section, Said lens 93 is held in position by a plate 95 which may be made of any suitable material and in practice has been made of Masonite. Plate 95 is secured to portion 52c by countersunk screws b. A small bracket 86 is secured to the underside of plate 521) at its forward portion by small screws 96a and has a lip extending downwardly and inwardly substantially at a 45 degree angle. A front plate 9'! is provided for the lamp box, the same having a latch 91a pivoted thereto by a pivot member 911), said member 98 being adapted to be moved over the inner side of bracket 96 to hold plate 91 in closed position. Plate 88 has small brackets 810 secured thereto, the same being offset to form lips directed toward each other and to extend over a mirror 98 which is thus secured to the inner side of plate 91. Plate 91 is hinged by a hinge |00 to the vertical stationary front side plate mm of the lamp box casing |0|. Side plate |0|a has secured thereto adjacent its bottom a resilient cushion block |00a against which plate 91 will engage should it be dropped. Casing |0| has a bottom plate |0|b having an aperture |0|c therethrough, one function of which is to admit cool air into the lamp box. The lamp box also comprises side plates |0|d which engage the outer side of flanges 522' formed on plate 52b and to which they are secured, Brackets I02 illustrated as formed from angle members are secured to side plates mm and extend across the lamp box adjacent the bottom thereof. Headed screws I03 extend through the lower part of bracket I02, being held therein by nuts I04, said bolts also extending through a plate I05 and being equipped with wing or thumb nuts |03a beneath plate I05, said nuts thus holding said plate in position. Plate I05 is centrally apertured and forms a seat for a ball member |06a formed on a rod I06 which extends through the bottom of the lamp box through opening |06c and carries at its upper end the lamp socket |06c in which the printing lamp I0! is secured. Rod I06 has a handle |06b at its lower end. A stationary contact member |08a forming one part of the printing lamp switch I08 is carried on a small angle bracket |09 secured to one side plate |0|b. The movable contact I08?) of switch I08 is carried on a pin N0 of insulating material being disposed at the inner and outer sides of side plate |0|b and moving with and forming in effect guide members for pin ||0 Pin ||0 extends through a vertically movable bar H2, said pin having a head formed thereon at the outer side of said bar and havin a small cotter pin ||3 extending thei'ethrough at the inner side of inner plate Bar ||2 extends downwardly through a slot 62a in plate 62 and has formed therein a notch |2a adapted to engage with plate 62 at one side of slot 52a as shown in Fig. 8. Bar 2 has adjustably secured thereon a block ||2b held in place by a screw 20 and said block is adapted to be engaged by a projection 83a on one of the rollers 83 in the revolution of plate 8|. This disengages notch ||2a from plate 63 and bar H2 is moved downwardly by a tensile coiled spring H4 secured to bar H2 at one end and at its other end to plate 63. A pilot lamp |0la is also provided in the bottom of lamp box casing IN. A second and condensing lens 93a is provided disposed at right angles to lens 93 and carried in an angle bracket |0|e and secured therein by headed and nutted bolts |0|d'. Spring Washers |0|f are disposed under the nuts on bolts |0|d' and Clamping members 93b which may be of resilient material are disposed under the heads of the nuts aseaeoa on bolts IOId and engage lens 03a. It will be seen from Fig. 9 that lenses 93 and 93a are flat on one side and have convex surfaces at their other side, said convex surfaces being directed toward mirror 90. A flat casing IOIh is disposed below plate 521) above lamp I01, the same containing insulating material IOIz'. Said parts are provided to prevent the heat from lamp I01 unduly heat ing plate 52b thereabove. An opening IOIa' leads from the-upper part of the lamp box and communicates with a vertical flue IOIlc which extends upwardly to the top of the machine. While said flue may be of any form, in the embodiment of the invention illustrated it is shown as rectangular in cross section.

The member 95a has an opening therein through which the light for printing passes and the top surface of member 35 forms the supporting surface for the negatives such as film which are to be printed. A negative holding means is provided comprising a rotatable plate or turret H5. Plate H5 is rotatably mounted on a pin H6 secured in member 52b and is arranged to be raised by a sleeve H1 disposed therebeneath and slidable on pin H6. A rest for plate H5 is provided comprising a headed screw I I5d adjustably threaded into member 52b and adapted to be held in adjusted position by a lock nut H5d. Sleeve H1 is adapted to be lifted by a lever H8 having end portions disposed at opposite sides thereof, said lever having parallel spaced portions joined at their ends remote from sleeve II'I. Lever H3 is arranged to tilt about a fulcrum member H3 carried on member 52b. An operating means for plate I I5 is provided and comprises a knee-operated lever I20 having a horizontal portion I20a journalecl in bearings I2I secured to the underside of table 52, said portion being bent at its end substantially at a right angle, and disposed to overlie the closed or outer end of lever H8. Lever I20 also has an outer downwardly extending portion I20b formed with spaced parallel sides, which portion is contacted by the knee of the operator. While lever I20 may be of any suitable form, in the embodiment Of the invention illustrated it is shown as made from a round rod. It will be seen that by pressing laterally on portion I20b plate H5 will be lifted and it can then be easily rotated about pin H6. Plate H5 has quite a number of circumferentially spaced opening H5a therethrough adjacent its circumference, which openings are of different sizes and shapes. Openings I I5a are thus adapted for use with negatives of different sizes and are adapted to determine different areas to be printed. Flat spring members H5c are secured at either side of one of the openings II5a and press on plate I I5 at the sides of said opening, said springs being adapted to hold certain small films or to engage a. special holding means for a very small film such as a strip film from a motion picture camera. Plate H5 is adapted to be held or locked in position with one of the openings II5a over the light opening 95a and for this purpose said plate is provided with a plurality of holes Hid, there being one for each opening H5a. When the respective opening II5a is in proper position relative to the light opening the corresponding hole II5d receives a pin H5e which upstands from member 52b. When the plate H5 is lifted for rotation it is lifted clear of pin I-I5e. A casing I22 having a substantially horizontal top I220 spaced a short distance above table 52 extends over holder H5, the same having outwardly and downwardly sloping sides. Said casing I22 is open at its front for the insertion and removal of the negatives and also has its top I220 offset upwardly at said front. The open front portion of casing I22 is closed during the printing operation by a flexible opaque curtain I23. Curtain I23 is weighted at its lower edge in any suitable manner as by having a, metal rod secured thereto at said edge. In the embodiment of the invention illustrated curtain I23 is shown as formed of a folded piece of material and a bar M311 is disposed in the bight or lower folded portion of the curtain, and forms the weight for the edge thereof. Said curtain and weighted edge overlap at their ends the downwardly and outwardly sloping front portion I22b of easing I22 which are disposed at each side of the opening in its front as shown in Fig. 9. Curtain I23 is moved to open and closed position by a crank rod I24 having the portion I24a extending across the underside of said curtain, said rod having portions I24b journaled in bearings in casing I22 at each I25a. is secured to pulley block I26. Crank rod I24 is oscillated through substantially 180 degrees at the beginning and end of each printing opera-.

tion and portion I24a folds and lifts curtain I23 to open position and then lowers it to closed position. The pulley block I26 oscillates at the beginning and end of each printing operation and moves through slightly more of a revolution than is necessary tov operate crank rod I24 and raise and lower curtain I23. Belt I250. slips on pulley I25. The curtain and crank I24 may be operated manually at any time if it is desired to look into the opening in casing I22. This can be done without throwing the operation of crank I24 and curtain I23 out of step or synchronism with the machine. The belt I25a will merely slip on pulley I25 and said pulley and crank rod will again be operated at the proper time in the operation of the machine by belt I25a from block I26.

Two rear rods I30 and forward rods I30a. and I30b are secured at their lower ends in top I22a and extend vertically to a three sided yoke I3I having forwardly extending parallel sides spaced at their front ends. While yoke I3I could be variously made, in the embodiment of the invention illustrated it is shown as in the form of a channel with its open side directed downwardly. Certain vertical rods or posts form guides on which are slidable two assemblies, one of which carries a projecting lens unit I33 having an adjusting means I34 and the other and upper of which carries the paper supporting and handling mechanism. Lens unit I33 is supported in a carriage on which is also carried a plate I33 having a forwardly curved upper end which extends over a plate I39 fixed to the top plate I22a, The other of said two assemblies constitutes a paper carriage and comprises a member I40 having rollers I40c slidable on rods I30a and I30b. Member I 40 at one side-has secured thereto a pulley I42 rotatable on a suitable headed stud. A cord or cable I44 is secured at one end to a lug I3Ia projecting from yoke HI and extends downwardly around pulley I42 and then upwardly and over a pulley I45 rotatable on a stud I48 secured in yoke I3I. From pulley I45 cable I44 extends downwardly and is connected to a suitable counterweight movable vertically to balance member I40 and parts carried thereby. Member I40 has projecting forwardly therefrom a bail handle I50. Rod I30a has a rack I30e formed on or secured to its outer side with which meshes a small pinion carried on a shaft journaled in member I40 which has secured thereto at the front of member I40 a small hand wheel I53. It will thus be seen that member I40 and parts supported thereon may be raised and lowered by handle I50 and that accurate adjustment may be had by turning hand wheel I53. The movement of the paper carriage is quite free and easy due to said counterweight.

The lens carriage and paper carriage are thus interconnected and arranged for determined relation and movement so that tl-e image projected by the lens will always be sharply focused on the paper by lens unit I33. The connections between said casings includes a bell crank lever I55. The aper carriage I40 has secured thereon by plate brackets IEI a. plate glass member I62. A platen carrier in is provided and is swingable about a shaft I65. Shaft I54 is driven from shaft I21 through bevelled gears I63 and I54. A mask carrier is disposed beneath the platen carried by carrier I12 and said mask carrier and platen are adapted to swing upwardly and rearwardly at the end of the printing period to discharge the print. Mechanism including a counterweight I94, a cam I82 and cam roller I81 are provided for operating the said platen and carrier which need not be specifically described. The print is discharge and is guided into any suitable receptable. A numbering device 208 is provided and is swung to place a number on the print at each printing operation. An exposure giude or meter is provided and this comprises a casing 230 secured to the central part of paper carriage I40. A mirror 233 is supported on this casing. A small casing in the rear of said mirror contains a lamp. The front of casing 230 at its upper portion is provided with a plurality of holes or openings 234a and these will have extending thereover a diaphragm or sheet of material so that light will show through holes 234a in difierent degrees of density. These openings may be designated by certain characters as shown in Fig. 1. A pointer is adapted to move along holes 234a. A scale is shown below mirror 233 with which cooperates a movable pointer 246a.

An index member 233 comprising a cylinder carried in end members 222 is used along which moves a small casing 225 containing a lamp 226 and supported by a bracket 224. Index member 223 is supported upon collars 222 revolubly mounted on a rod 22I secured in yoke I3I. A print grinding panel 2I0 is provided at the rear of the machine.

The structure described in the last three paragraphs form no part of the invention claimed in this application and need not be more specifically described.

As stated, an exposure guide or meter is provided (see Figs. 11 to A casing 230 of general rectangular form in vertical cross section is provided, the same being secured to the central part of aper carriage I40. A plate bracket 23I extends across casing 230 adjacent the bottom and forward portion thereof, being secured by screws 232 and forms a support for a mirror 233. Said bracket also supports a small casing 234 in casing above switch 2'.

the rear of said mirror which contains a lamp 235 shown as of elongated cylindrical form, the same being carried in a socket 236 secured to one end of casing 230. The front of casing 234 at its upper portion is provided with a plurality of holes or openings 234a and these will have extending thereover a diaphragm or sheet of material 231 of such nature so that light will show through holes 234a in different degrees of density. As shown in Fig. 12 the opening at the right is quite dark and the openings are progressively lighter toward the left. These openings may be designated by certain characters as shown by the numerals in Fig. 12. A bar 238 extends across the top of casing 230 being secured by screws 233, which bar has slidable thereon a pointer member 240. Below casing 234 is a cylinder 24I having a resistance conductor 242 wound thereon. Said cylinder 24I is held in apertures in spaced brackets 243 secured to casing 234 by screws 244. Brackets 243 also carry at their lower ends a bar or rod 245 on which is slidable a contact member 246 adapted to cooperate with the resistance member 242. Member 248 also carries a pointer 246a which cooperates with a. scale 241 visible at the front of casing 230. A clock motor 240 of the conventional back geared type is mounted in casing 230, the same driving a clutch disk 249a of the clutch 249. An electromagnet 250 is provided, said magnet and motor being carried by a bar 25m extending across and secured in casing 230. The electromagnet 250 operates a clutch fork lever 25I which is arranged to engage and move a clutch disk 249?) of the clutch 249 to bring the same into engagement with disk 249a.. Disk 249a is shown as having its fiat surface covered with some suitable friction material 249a. A small compression spring 25!!) is disposed between the disks 249a and 24917 and a coiled torsion spring 252 is secured to the back of disk 24917 and to a bar 253 forming part of the motor and magnet frame, which frame also carries the clutch. Disk 24% is carried by a shaft 254 to which is secured a pulley 255. A belt 256 illustrated as of cylindrical cross section is secured at one end by a small screw 251 to pulley 255, the same extending partially around said pulley and then around a pulley 258 carried on a shaft 250 suitably supported in casing 230 and around a similar pulley 260 carried on a shaft 26I supported in casing 230, said belt then again passing to pulley 255 and having its other end secured to said pulley by a small screw 262. The winding of the electromagnet 250 will be in circuit with the printing lamp I01. Belt 258 is connected to the member 240. From the described structure it will be seen that when electromagnet 250 is actuated lever 25I will engage the disks of clutch 249 so that pulley 255 will be driven. Belt 256 will be driven and the same will travel around pulleys 258 and 260 so that the pointer member 240 will travel across bar 238 above the openings 234a. When electromagnet 250 is deenergized the clutch disks 249a and 24919 are separated and springs 252 will rotate disk 249D and pulley 255 so that the belt 256 will be moved and the pointer 240 will be moved back to its position at the left as seen in Fig. 11. A switch box or casing 210 is carried on one side of the machine as shown in Fig. 2 and a main switch 2' has an operating handle projecting through an aperture in said casing. A small ruby lamp 212 is mounted on said switch A conductor 213 is shown extending from switch casing 210 to the either enter the lamp box casing IN or be brought into switch box 218.

The machine has a series of shelves 288 illustrated as three in number extending horizontally at one side thereof beneath table 52 and supported upon vertical bars 28I secured at their upper ends to table 52 and achannel member 282 extending across the same. Drawers 283 are adapted to be disposed on the shelves 288, the same Having Y handles 283a on their front ends. A shelf 284 is formed at the right side of the machine, the same sloping downwardly and forwardly at an angle of substantially 45 degrees and having an upwardly and forwardly extending portion 284a at its lower end. The shelf 284 is adapted to support one of the drawers 283, which drawers as shown in Fig. 1, are provided with a plurality of compartments 283?) and are also provided with a cover 2830. Beneath shelf 284 the machine is provided with a plurality of vertically extending compartments 285 divided by vertical partitions 288. Forwardly of the foremost partition 288 the machine is pro vided with a plurality of compartments 28! formed by partitions 288 having rounded forward corners.

In operating the machine, the main switch 2' is moved to closed position and this starts the motor 51, lights the index lamp 228 and lights the pilot light I8'Ia. The function of the pilot light is to furnish sufficient light for the operator to place the negative over the light opening 85a. It will be understood that the machine will be operated in a dark room. The operator now takes the negative to be printed and selects the proper mask to give the desiredenlargement or the desired size of print. It will be understood that at this time the platen is in its rearward position. The mask is quickly placed in position and the operator now presses laterally on the downturned portion I28b of lever I28, thus lifting negative holder I I5. This holder is thus free for rotation and is quickly turned to bring the desired opening H51! in forward position. A negative is placed beneath the opening II5a and lever I28 is released. Plate I I5 then descends holding the negative firmly on the top of plate 95. The inter-connection between the paper carriage I48 and the lens carriage I32 is so designed that the lens unit I33 is always brought to proper position so that the projected image will fill the mask opening. The paper is now placed in position. The operator now presses on the trigger plate 88. This, through arm 84, raises the plate 8i, bringing the lower clutch plate I8 into engagement with upper clutch plate 88. The clutch is now engaged and rollers 83 have been raised out of the slots 58a and rotate about on the top of plate 58. When the lower plate I8 begins its movement arm I3 is rotated and this, through the link I4, rotates the arm 15. As above described, this rotates shafts I3 and I2! as well as shaft I85. The platen holder I12 is now swung down to paper holding position. At the same time the printing member is pressed against the paper on the non-emulsion side and the identifying character is printed on the paper. This character is usually the same for all of the prints on the particular order. This number of course, may vary as directed by the customer. As the platen reaches its position on the paper, plate 8| has revolved into position to bring projection 830 into engagement with block I no on bar I I2. This disengages notch II2a from plate 83 and said bar drops, thus closing switch I88. The closing of switch I88 lights the printing lamp I81, lights the lamp 238 in the exposure guide housing, actuates electro magnet 258 and starts the motor 248 so that pointer 248 starts to travel along the openings 234a. As shaft I21 rotated during the operating of the pulley, block I28 was rotated and this. through belt I280, rotated pulley I25, thus moving crank rod I24 and lowering curtain. I23

to its closed position. Curtain I23 thus closed the opening of casing I22 before the printing lamp was lighted. When the printing lamp is lighted the image as stated, is sharply focused on the printing paper. This image is reflected in mirror 238, which as shown in Fig. 1, is in view of the operator. The operator glances at said image and picks out a portion thereof which will determine the printing period. Every negative has certain contrasting parts therein and an experienced operator in looking at the negative can and does pick out some portion thereof which will determine the density of the print to be made or the time of exposure. Having selected the said portion of the image the operator thenselects the opening 234a which most nearly corresponds to the density of the selected portion. If the selected portion is very dark then the opening at the right as shown in Fig. 12 and which is numbered I5 would be selected. If a lighter portion has been selected, perhaps spot or opening I would be selected. The openings 234a in effect form spots. The spots are designated by numerals in Figs. 12 and 15. This is not absolutely necessary but the numerals indicate the multiple of density of the particular spot in relation to the spot marked I. In other words, the spot marked 2 is twice the density of the spot marked I and the spot marked 4 is twice the density of the spot marked 2. If desired, the spots could be arranged in a regular geometrical series of density. In practice, the pointer travels from the first spot to the last in about 20 seconds. The printing period will of course, var with the kind of printing paper used. In the common practice in the art, printing papers of different speeds are used. To adjust the exposure guide for different print papers the pointer 248a is provided with the resistance 242. If a very fast paper is used, the pointer 248a will be adjusted to cut in resistance so that the lamp 235 will be dimmed and all of the density spots in openings 234a will be darkened. If a slow paper is to be used resistance will be cut out so that all of the density spots will be lightened in color. The indications on the scale 24'! indicate different papers and pointer 248a will be placed in registry with the number designating the paper used at any particular time. As soon as the pointer 248 has reached the selected spot or opening the print will be finished and the operator then again steps on trigger plate 85. When th trigger plate is again pressed upon, the bar I I2 will be raised and the printing lamp will be extinguished by the opening of the switch I88. It may be here pointed out that the trigger plate has two functions. One is to connect the clutch plates 89 and 18 and the other is to control the printing lamp after the printing operation. It is some times desired to doctor a print by giving one portion a little more exposure. An operator often does this by placing her hand or an instrument over a portion of a print or between the lens and the paper. This is a well known operation and can be done very quickly by an experienced operator. The operator may therefore, raise and lower trigger plate 86 several times quickly to light and extinguish lamp I07 before pressing the trigger plate down far enough to again operate the clutch. If no doctoring is to be done on the print the operator merely presses the trigger plate down all the way and this raises plate 8| and again operates the half revolution clutch comprising plates 69 and 10. When the clutch is engaged it makes a half revolution and arm I3 is again rotated, which through the mechanism described, operates shaft I21 and also as above described, shaft I65 is operated. This raises the mask carrier and platen together lifting the print and discharging it rearwardly. As above described, the mask carrier is returned to print receiving position and the platen remains in its rearward position. The print slides from the platen against panel 2 l8 and then drops onto a deflecting plate and is guided into tray 220. The operation is quite rapid and the making of prints is only a matter of seconds. The lighting system illustrated is that using a projection lamp and condenser lenses which are the lenses 93 and 93a. As stated, these are pianoconvex lenses. The lens 93a directs the rays in substantially straight lines against mirror 98 by which they are reflected upwardly into lens 93 which focuses the rays for direction into the lens unit I33. The projection lamp is extinguished a sufficient time before the print is raised for discharge that no difliculty is experienced with afterglow from the lamp. The operator can make a quick adjustment of the iris or diaphragm if this is necessary to suit the particular negative by merely swinging arm I34 to the desired position.

The lamp box is ingeniously made for easy access and-cleaning. When the hinge side 91 is swung downwardly the lenses 93 and 93a may be cleaned or polished as can also the mirror 98 and access can be had into the casing IOI if desired. The rear side of the lamp box casing IOI is removable as indicated by the dotted lines in Fig. 9. This gives easy access to the inside of the casing and lamp bulbs I01 and Wm may be replaced when necessary. Easy access is thus also had to the switch I08. It is necessary to accurately position the printing lamp I01 relatively to lens 93a. The bulbs used may be of different sizes and the filaments vary in different bulbs. Rod I08 is slidable frictionally through ball M511 and this movement, together with the universal movement possible with ball I06a in the plate I gives all the necessary adjustment. The ball I 06a is made in half sections which are clamped on rod I06 by bolts I03 and the nuts I03a. One section has a hole for rod I06 extending centrally therethrough while the other section has the hole for rod I06 extending to an acute angle to the flat side thereof. The adjacent flat surfaces are then at an angle to each other. When the sections are clamped together by nuts I03a the ball exerts a pinching effect on rod I06 thus holding the same and lamp I01 firmly in adjusted position.

The lamp box is ventilated to prevent excessive heating by cool air entering through the openin He and passing around the partition carried on brackets I02 as shown in Figs. 9 and 10. This partition forms a sort of a flue at the bottom and side of the box and the cool air then passes into opening I0l7' and into the flue IOIk which extends to the top of the machine. There is enough height to the flue to get a good draft and the ventilatin g is quite effective.

The masks used can conveniently be kept in the compartments 285. The work order envelopes containing the films for each order can conveniently be placed in the compartments 281. The drawer 283 contain the print paper and paper of different speeds will be contained in the compartments 2133!). The. drawers can be conveniently positioned on the shelf 284 so that the paper is within easy reach of the operator. Another important feature of the machine is the trough formed in the rear of flange 520. As the work is finished on each negative the operator can mere- 1y push the negatives forwardly so .that they drop into said trough. When the particular order is finished the operator can reach into the trough with the thumb and finger through the opening 52d and grasp the pile of negative between the thumb and finger so that they can be easily and quickly removed as a group. This adds to the rapidity of the operation.

The machine as described, is adapted to produce various standard sized paper prints from one size negative. This can be done by using the various masks provided and making the necessary adjustment on the index for the masks.

The machine can be used to produce various standard sized paper prints from different sized negatives. For instance, the prints can be made in such standard sizes as 4 by 6 inches, 5 by 7 inches and 6 by 8 /2 inches by selecting the masks for those standard sizes and then using the different sizes of negatives in the proper holders or openings in the negative holder. If only one standard size of print is desired, the mask corresponding to that size would be used with the different sized negatives.

The machine can alsobe used to produce single sized prints from one negative with various magnifications. For instance, a certain mask, say a 4 by 6 mask, would be selected. The negative then could be enlarged to include all of the subject matter to cover the 4 by 6 print or onely a small part of the negative could be used to fill the 4 by 6 print. The hand wheel I 53 may be turned somewhat to move the paper carriage upwardly a short distance and this increases the magnification of the central part of the negative. This procedure is frequently desired to eliminate some uninteresting subject matter about the edges of a negative.

The machine can also be used to produce single sized prints from diiierent sized negatives. In this case only one size paper mask would be used and the different sized negatives would be placed under the different openings I I5a. As each opening is brought over opening a, the paper and lens carriage would be adjusted to the proper letter.

The machine can also be used to produce prints with wide margins of different widths. This can be done by using a piece of paper lar er than the image desired and using a mask which covers a large part of the paper about the edges thereof.

The negative holder holds each negative in the exact center of illumination. The negative holder being operated by the knee-operated lever leaves the hands of the operator free for other uses.

From the above description it will be seen that I have provided a very efficient and compact machine by'means of which enlargements or oversized prints can be made with great ease and speed. The machine has been amply demon strated in actual practice and found to be very successful and efficient. It is being put into commercial production.

printing machine having in combination, a support having an opening therethrough and adapted to support a negative, means for projecting light through said opening and negative supported thereon for printing from said negative,

a mirror in which an image of said negative is reflected in position to be viewed by the operator, a-density scale comprising areas of graduated density adjacent said mirror with which the reflection of said negative may be compared, a member movable along said scale, .means for starting the movement of said member when said first mentioned means is actuated and means under the control of the operator for rendering inoperative said first mentioned means and stopping the movement of said member and the printing operation when said member reaches a selected point on said scale.

2. An exposure guide device for a photographic printing machine having in combination, a support having an opening therethrough, and adapted to support a negative, means for projecting light through said opening, and negative supported thereon, a mirror in which the image of said negative is reflected in position to be viewed by the operator, 9. density scale comprising areas of graduated density adjacent said mirror with which the reflection of said negative may be compared, a member movable along said scale, means for moving said member including a clutch, means for operating said clutch including a magnet, an electrical circuit including said first mentioned means and magnet, a switch for opening and closing said circuit whereby when said switch is moved to close said circuit said first mentioned means will be actuated and said magnet will be energized to operate said clutch and start movement of said member.

3. An exposure guide device for a photographic printing machine having in combination, means carrying an image of a negative and disposed in view of the operator, a density scale located near said means so as to be viewed simultaneously with said image and having spaced areas graduated in density whereby the operator can select a portion of said image corresponding to the density of one of said areas, means moving along said scale at uniform speed coincident with the printing period and means under the control of the operator for terminating the printing period when said means reaches said area on said so e.

4. The structure set forth in claim 3, means for illuminating said areas and means for adjusting the degree of illumination for varying the density of all of said areas.

5. An exposure guide device for a photographic printing machine having in combination, means in which an image of a negative to be printed is visible to the operator, a graded density scale disposed near said means so that the operator can view said negative and select a portion thereof and a point on said scale having substantially the same density, a member movable along said scale with a, uniformly timed movement, means for starting the movement of said member from one end of said scale and simultaneously starting the printing period, and means actuated by the operator for terminating the printing period when said member reaches the selected point on said scale.

6. A device for determining the exposure period of a photographic negative having in combination, a transparent means for supporting a negative, means for projecting light through said negative for printing therefrom, means carrying an image of said negative in view of the operator, a density scale near said last mentioned means comprising spaced areas having respectively graduated densities so that the operator may select a portion of said negative from said image and select an area on said scale corresponding to the density of said portion, a member movable along said scale at uniform speed, means for simultaneously operating said second mentioned means to start the printing period and starting ,the movement of said member, and means for terminating the operation of said second mentioned means and thus terminating the printing period when said member reaches the selected area on said scale.

7. An exposure guide device for a photographic printing machine having in combination, means carrying a reflected image of a negative, a density scale near said means having areas with graduated densities said image and scale being disposed to be viewed simultaneously by the operator, a member movable at uniform speed along said scale and means for simultaneously starting the movement of said member along said scale and starting the printing period, and means under the control of the operator for terminating the printing period and stopping the movement of said member when the latter reaches a selecter area on said scale.

8. The structure set forth in claim 1, means for illuminating said areas of said density scale, means for varying the illumination of said areas, a second scale for indicating degrees of density, said last mentioned means including a pointer movable along said second scale for indicating the selected degree of illumination.

GLEN lid. DYE. 

